The ECU has to be programmed to recognize the chip in the new key. The item in your picture just reads the chip info and passes it to the ECU.
To silence the the alarm, open the hood and disconnect the wire that connects to the hood latch. Jumper the connector. That will fool the security system into thinking the hood is always open and will not arm the alarm.

 

The blue light on the dash no longer comes on telling me that the key is wrong.

I got the locksmith out there to do the keys and he said there's no power to the OBD2 port so that being said I have no power to the OBD2 to program the keys and I can't find a fuse that would power the OBD2 port.
so that's the next thing on the list and as far as I was told that the immobilizer module called the ignition immobilizer I was wrong on the name. Auto programs the computer.

Honda dealership said the manual programming of the key was not started until the 2007.

I'm not sure if thats accurate. I'll send over pictures of parts missing. Such as a plug under the steering column with no obvious destination.

Much appreciated.

 

The blue light on the dash no longer comes on telling me that the key is wrong.

That's odd, the Red light (Security System Indicator) on my dash blinks when the Alarm is armed. It's the key (Immobilizer System Indicator) that flashes to indicate issues with the ignition key. It's in your Owner's Manual. (Maybe the color changed from '02-'03, but the location is the same.)

And here's the info about the Immobilizer System:

 

First of all, you need to make sure that this is indeed a factory intact immobilizer and not some 3rd party system. I mention this because you said there is no blue light on the dash telling you the key is wrong... There is never a blue light on an 2003 Odyssey. There is a green key symbol in the dash that flashes when the immobilizer is not sensing the correct key. If it senses the correct key, it will light up for just a moment and then turn off when you have ignition on.

The way the system works is that the immobilizer unit has to be programmed to the ECU. And then keys have to be programmed to the ECU also. So if you replaced the immobilizer unit, you must first reprogram the ECU to accept and recognize that new immobilizer. After that, you have to then program the keys to the new immobilizer. All of this is done using the Honda HDS service tool. You cannot do this yourself unless you have access to the HDS system as well as to Honda's servers to get the immobilizer reprogram code that changes daily. Any Honda dealer should be able to do this for you, as long as it's a factory system and not a 3rd party one.

 

The way the system works is that the immobilizer unit has to be programmed to the ECU.

The part the OP replaced, the immobilizer receiver, is plug and play no programming required. It reads the code from the key and sends it to the PCM where it is validated.

 

Good news is. The ignition immobilizer was auto programmed. So the vehicle recognized the new keys. I noticed 15 fuses burned out in the van. I it has 6 fuse boxes. So im replacing all fuses and testing the spark plugs and fuel pump. One of the relays might be burned out. The wireless locks now work. Which they didn't before as well as the automatic sliding doors. Also. Prior to the key programming. When i would disconnect the battery and reconnect. The alarm would sound and honk in a morse code like pattern. Didn't do that today. Not sure if that is relevant.

 

Good news is. The ignition immobilizer was auto programmed.

Did you not see Dave's post?

The part the OP replaced, the immobilizer receiver, is plug and play no programming required. It reads the code from the key and sends it to the PCM where it is validated.

It's not that it was 'auto programmed', it did not need to be programmed.

With 15 fuses burnt out- no wonder you're running in circles trying to fix your problem.

 

Hey everybody thank you for inviting me to the Odyssey Club I wanted to ask some people who have experience in this area.


I have a 2003 Honda Odyssey that I bought and shortly after buying it the ignition was replaced due to bad key. we also discovered that the immobilizer bypass module that goes around the ignition key
View attachment 161302
became bad so we replaced it and we're looking for some help on repairing the van because the ignition immobilizer bypass module was replaced. now the horn is honking and the van security system is I guess offline. I'm not sure on honda. This is the first honda product ive ever owned. Honda said they do not have the tools to reprogram this van. So taking it to a dealership is a waste of time.

any help here would be hot. I never had issues with this on my Ford freestar 😂😂😂😂😂.


Anyway go ahead and ask me questions if you need to thank you everyone

CEO Brandon Gibson
Megalo Technologies Corporation
Megalo Social Media
Branson Missouri!!!!

 

My ignition antenna coil (immobilizer module? broke and I cannot find a replacement anywhere. Per Honda, that part is discontinued. Can you please tell me where you found it? Thanks.

 

what if the green key light dose not come on at all

 

Most likely, the bulb is burned out.

Otherwise, the wiring between the PCM and the bulb is bad.

Most unlikely, the PCM is bad.